To explore the value of ultrasound diagnosis of exploring the deep vein thrombosis (DVT) of left lower extremity complicated with Cockett syndrome.

The sonographic appearances of 123 patients with DVT of left lower extremity were analyzed retrospectively and they were divided into Cockett syndrome group and non Cockett syndrome group (control group) based on the result of DSA.The inner diameter, flow velocity of proximal vessel (d1, v1), distal vessel (d2, v2) of left iliac vein, calculated the ratio of d2/d1 and v1/v2 were calculated.

Seventy-eight cases were diagnosed as Cockett syndrome by DSA, 70 of them were detected by ultrasound.The accuracy, sensitivity and specificity of Cockett syndrome by ultrasound were 93.5%, 89.7% and 100.0% respectively.The result of ultrasound demonstrated well coherence (Kappa=0.865) of the diagnosis of DSA.Compared with the control groups, a significant reduction of inner diameter [d1, (2.1±0.3)mm] as well as an increase in flow velocity [v1, (79.3±19.2)cm/s] was observed in the proximal vessel of left iliac vein in the Cockett syndrome group(t=6.22, 5.83; P<0.01). The d1 (2.1 mm) or v1/v2 (6.0) used as the indicator for diagnosing Cockett syndrome, the accuracy, sensitivity and specificity were 76.8%, 71.3%, 83.6% and 77.4%, 74.5%, 82.6% respectively.

Ultrasound is a reliable method for the diagnosis of the DVT of left lower extremity complicated with Cockett syndrome, which has great significance for clinical diagnosis and treatment.